1. Technical Field
The present disclosure relates to a bidirectional switch formed of a semiconductor chip comprising a main electrode on each surface of the chip and a control electrode on the front surface of the chip, this control electrode or gate being controlled by a voltage referenced to the voltage of the rear surface electrode.
2. Discussion of the Related Art
Such components are different from unidirectional thyristors and from bidirectional triacs in which the gate signal is controlled by reference to the front surface electrode. Having the gate electrode referenced to the rear surface is advantageous in that it is convenient to connect the rear surface comprising a single electrode to a ground plate or a radiator, which enables the gate signal to be referenced to a fixed voltage, for example, the ground, while in many applications, the main front surface electrode is connected to the mains voltage, which make it necessary to provide isolation systems to deliver a voltage between a control signal and a variable potential.
The applicant, which has created the concept of bidirectional switch referenced to the rear surface, sold under trade name “ACS”, has conducted many studies on these components. U.S. Pat. Nos. 6,034,381, 6,593,600, and 6,927,427 will especially be mentioned. Further, previously, the applicant had provided to connect multiple unidirectional components (thyristors) in parallel with a common cathode, the gates being referenced to the cathode, as described in U.S. Pat. No. 5,914,502.
The various known architectures of bidirectional rear surface referenced switches, when controllable in Q1 and Q4 modes, that is, when the gate is positive with respect to the rear surface electrode, have the disadvantage of involving a transistor or a lateral thyristor for their turning-on. This sets, on the one hand, an issue in terms of surface area assigned to the gate, and on the other hand, possible latch-up problems when an abrupt voltage variation is applied between the main electrodes (dV/dt turn-on).